This invention relates to particle orientation imaging, and, in particular, to a system for creating images by selective imagewise orientation of particles suspended within a softenable electrically insulating layer.
Some particle orientation imaging processes have been employed to develop imagewise reproductions.
One such process is disclosed in U.S. Pat. No. 3,485,621. There, a recording method is disclosed wherein plate-like diamagnetic anisotropic particles are dispersed in a thermoplastic layer and selectively reoriented by application of an electrostatic field transverse to said layer while said layer is held in a softened condition. To record data by means of an optical input system, it is herein taught that a photoconductive sheet must be placed over the film surface and in contact therewith. The photoconductive sheet receives the optical data and converts it into an electrostatic charge pattern on the film surface.
Another patent which is encompassed by the board category of particle orientation imaging is U.S. Pat. No. 3,513,449. Disclosed therein is a recording media comprising a pre-oriented dispersion of dichromophoric photoconductive bodies contained in an insulating softenable matrix. The radiation used in exposure is highly coherent, relatively monocromatic electromagnetic radiation.
U.S. Pat. No. 3,171,106 discloses orientation of magnetic particles dispersed in a thermoplastic storage medium by means of magnetic fields. Read-out is by means of an electron microscope optical system "responsive to the alignment of the axis of the magnetic particles." More specifically, the medium is made plastic by heating; the particles are first uniformly aligned and then selectively oriented; finally, the medium is hardened and ready for storage and/or read-out.